Stereo Scan 440 - DCU

One further complication is that on the Stereoscan 440 it is possible to map PC
DRAM into the C8000 to CFFFF area and load device drivers into this area. thus
saving space in the DOS application area. This will not happen if there is
hardware occupying this range and therefore the EMM386.EXE used to control
access to the area will have been loaded unnecessarily.
va Space
Expansion cards are most likely to include a set of registers with which to conb'ol
the card. These are usually I/O registers occupying space in the I/O map of the
Stereoscan 440 PC (as opposed to the memory map. see above).
The cards fitted must be configured not to clash with the existing registers.
There is however some scope for disabling registers on the PC card in the
Stereoscan 440's when other options are fitted, this is a trade off between items.
For example, if an internal modem card is fitted. then it is usual to configure it at
the address occupied by a serial COM port and to disable the existing serial COM
port.
The following shows the I/O map of a Srereoscan 440:-
Addftas
{XX}-O 1 F
020-03F
O4O-OSF
CWJ-O6F
070-07F
OSO-O9F
OAO-OBF
OCO-ODF
OEO-OEF
OFO-OFF
lOO-IEF
lFO-IFF
200-207
1- Device
I DMA Co~!l~_l
I IntemlDt ~ontroller 1
I Time~
I
K~~board Controller
I Real TID1e Clock
.I DMA ~e Re~rs
Interrupt Co~Uer 2
DMA Controller 2
j R~erved for maths~~sor
I Fixed Disk Coot!"aJJer
I Reserved for Games Port
Stereoscan 440 Operator Manual